1. Field of the Invention
The present invention relates to a slice image display apparatus and method for displaying a slice image based on voxel data that represents spatial distribution of an object as a three-dimensional image. Further, the present invention relates to a computer-readable recording medium having stored therein a program for the apparatus and method.
2. Description of the Related Art
In recent years, as CT (computed tomography) apparatuses and the like have been developed, it has become possible to obtain tomographic images that accurately represent anatomical structures of human bodies. Further, three-dimensional images have been reconstructed based on a plurality of tomographic images obtained by imaging a subject at different sectional positions (slice positions).
In a method for displaying a three-dimensional medical image, the three-dimensional medical image is generally handled as a three-dimensional array of voxels having voxel values (pixel values) corresponding to the structures of a subject. In one of major methods for displaying the three-dimensional medical image, an arbitrary slice plane of the three-dimensional array of voxels is displayed by performing slice-plane transformation processing (for example, Multi-Planner Reconstruction, hereinafter, referred to as MPR).
When a doctor or the like diagnoses a patient by using image data obtained by imaging by a CT apparatus or the like, they observe slice images generated by performing MPR processing. In many cases, an axial image or a coronal image on a plane parallel to a CT image, or a sagittal image on a plane perpendicular to the plane parallel to the CT image or the like is generated as a slice image, because such slice planes can be easily set.
However, in actual diagnosis, there is a demand for observation of arbitrary slice images that are called as oblique images. When a shadow that is likely to be a node (knot) is found, the inclination angle (inclination direction or the like) of the slice image is changed in the vicinity of the shadow by using a mouse or the like to observe slice images.
For example, Japanese Unexamined Patent Publication No. 6(1994)-337920 proposes a method for generating an arbitrary new slice image that passes through a region of interest in the slice image and that has been rotated by a predetermined angle.
In the method proposed in Japanese Unexamined Patent Publication No. 6(1994)-337920, slice images are generated based on operations of changing the inclination angles of the slice images by a mouse or the like. The inclination angles are changed to all angles, using a region of interest in the slice images as a base point. Further, the operations must be repeated, and that is troublesome.